bug: git credentials helper strips wwwauth[] on HTTP redirect

Thank you for filling out a Git bug report!
Please answer the following questions to help us understand your issue.

What did you do before the bug happened? (Steps to reproduce your issue)

Ran `git push` to a remote whose URL 301-redirects to a new path before the
server responds 401 with a WWW-Authenticate header.

What did you expect to happen? (Expected behavior)

wwwauth[] to be passed to my credential helper, as it is when pushing to the
same server without a redirect.

What happened instead? (Actual behavior)

wwwauth[] was empty, so the helper couldn't detect the auth scheme.

What's different between what you expected and what actually happened?

The redirect causes wwwauth[] to be dropped

Anything else you want to add:

The credential helper in context is
https://github.com/hickford/git-credential-oauth
The server is a self hosted forgejo https://forgejo.org/

Please review the rest of the bug report below.
You can delete any lines you don't wish to share.


[System Info]
git version:
git version 2.55.0
cpu: x86_64
no commit associated with this build
sizeof-long: 8
sizeof-size_t: 8
shell-path: /bin/sh
rust: disabled
feature: fsmonitor--daemon
gettext: enabled
libcurl: 8.15.0
OpenSSL: OpenSSL 3.5.7 9 Jun 2026
zlib-ng: 2.3.3
SHA-1: SHA1_DC
SHA-256: SHA256_BLK
default-ref-format: files
default-hash: sha1
uname: Linux 7.1.5-101.fc43.x86_64 #1 SMP PREEMPT_DYNAMIC Tue Jul 28
14:24:13 UTC 2026 x86_64
compiler info: gnuc: 15.2
libc info: glibc: 2.42
$SHELL (typically, interactive shell): /bin/bash


[Enabled Hooks]
not run from a git repository - no hooks to show